I have produced the O-scape extensions to enable the creation of Orienteering maps using Inkscape.
I am producing a map of an urban area, which is larger than A3 paper size at 1:4,000.  The SVG file is currently 2,126KB with over 3,200 objects (and counting) and has three linked (not embedded) image files; two maps and aerial imagery from Google Maps.
Most of the map has been produced using standard Inkscape functionality for lines and shapes.  Now, though, when I want to convert a line to a special line type (such as a tagged line representing a fence), the extension runs very slowly and sometimes crashes Inkscape.  Sometimes Inkscape 'loses' the aerial imagery, instead displaying a low res image saying 'Linked image not found' at which point I can save and exit normally.  Other times, Inkscape crashes with the following message - 'GLib-Error **:gmem.c:175: Failed to allocate 134217728 bytes aborting...'.  I've tried running other extensions, not just my O-scape ones, with the same results.
I'm running Inkscape in Windows Vista Home Premium on an Intel Core2 6600 @ 2.40GHz computer and have recently increased the available RAM from 2GB to 4GB.
Am I reaching the limit of Inkscape?  Is there some way that I can alter my set-up to a) make extensions fun faster, and b) stop the extensions losing the linked files or crashing Inkscape?